class Dongwu {
  void cry() {
  }
}
class Gou extends Dongwu {
  void cry() {
    System.out.println("汪汪汪……");
  }
}
class Mao extends Dongwu {
  void cry() {
    System.out.println("喵喵喵……");
  }
}
public class Example5_11 {
  public static void main (String args[]){
    Dongwu animal;
    animal= new Gou();
    animal.cry();
    animal=new Mao();
    animal.cry();
  }
}
